In petroleum exploration and production, it is well known to drill for oil in a sub-sea environment. It is also known that during drilling or production, unanticipated pressure surges may occur at the well head, leading to an uncontrolled flow condition known in the art as a “blow-out” wherein flow control of the emerging crude oil is lost. Such blow-outs are costly at least in terms of lost time and production; and when a blow-out continues for an extended period of time or in very deep water, as has been seen recently in the BP blow-out incident in the Gulf of Mexico on Apr. 20, 2010, the environmental and financial consequences can be catastrophic.
Typically, wells that are drilled on land or underwater are drilled through a generally cylindrical safety device mounted at the well head known as a “blow-out preventer” (BOP). A typical BOP includes a compressible collar that can be clamped about a drill stem to seal the well should a potential blow-out occur with the drill stem in place, and further includes a plurality of redundant valves that can be closed to shut off a blow-out or other leakage from a producing or exhausted well. However, in blow-out instances wherein no BOP was employed or wherein the BOP was inoperative, additional control is required. For land-based drilling operations, it is well known to seal a blown-out well with heavy equipment and/or explosives. For underwater blow-outs, these options are not generally available, especially in very deep water where all remediation must be conducted remotely, in darkness, and at greatly elevated pressures.
What is needed in the art is a simple method and apparatus to shut off uncontrolled flow of crude oil from an underwater oil well, preferably to allow continued production to the sea surface from the well.
It is a principal object of the present invention to stop the uncontrolled flow of crude oil from an underwater oil well into the surrounding sea environment.
It is a further object of the invention to capture and recover crude oil continuing to flow from the well.